1. Field of the Invention
The present invention relates to a communication terminal, a communication system and a communication method for making communication by selectively using a plurality of sources (tools).
2. Related Background Art
Recent advancement of compression coding technologies for video information, image information and audio information and population of digital communication lines are remarkable. As a result, recommendations such as service regulations and protocol regulations for AV (audio visual) services and multimedia multiplexing frame format regulations have been proposed.
The video information means motion picture information which can be electronically processed and which may be read into and from a computer through a video board. The video information may also be controlled such as play, stop and pause by a conventional computer application. It may also be recorded to and reproduced from a video equipment.
The image information means still image information which can be electronically processed and wich may be read into the computer by a scanner and created by a draw tool which is one of computer application software. Like the video information, the image information may be outputted to a monitor such as a CRT or an LCD.
The audio information means sound information which can be electronically processed and which may be read into the computer through a microphone and created by a synthesizer. The audio information may be outputted to a speaker. It may also be recorded to or reproduced from an audio equipment.
The electronic information may be transmitted and received among remote stations through a network. A communication system, for example, a TV conference system or a remote lecture system in which the electronic information is communicated among remote stations to display scenes of lecture by terminals located at remote stations connected through the network and output sound by speakers in order to electronically hold the lecture among the remote stations has been proposed.
In such a communication system, the information displayed on the monitor may be displayed in enlargement by using a scan converter or directly by using a projector. By registering image files in a form of list by a draw tool, the image files may be clicked by a mouse to sequentially display them.
The video information and the image information may be selectively outputted or transmitted by controlling a conventional switcher by the computer. In the past, an information switching process by a lecturer has been implemented by a flow chart shown in FIG. 10.
In FIG. 10, when an image switching process program is started, an event such as a key entry or mouse click is monitored in a step S1001. For example, as shown in FIG. 1, a switch 11 for switching the input information is displayed on a monitor screen to prompt a user to enter input information.
A xe2x80x9cCameraxe2x80x9d switch at the left end is a switch for selecting input information from a camera and a xe2x80x9cVideoxe2x80x9d switch next to the left end is a switch for selecting input information from a video equipment. A xe2x80x9cDrawxe2x80x9d switch at the third from the left end is a switch for selecting input image information read by an OHP (overhead projector) or image information created by a draw tool.
When the input information from the camera is selected by the user, the process proceeds from a step S1002 to a step S1003 to read the input video information of the camera and corresponding audio information into the computer. The video information thus read is displayed on the monitor in a next step S1004.
In a step S1011, the video information displayed on the monitor is outputted to a projector, and in a step S1012, the audio information read in the step S1003 is reproduced. At the same time, in a step S1013, the video information and the audio information are transmitted to the network.
When the input video information from the video equipment is selected by the user, the process proceeds from a step S1005 to a step S1006 to read the input video information of the video equipment and corresponding audio information into the computer. The read video information is displayed on the monitor in a next step S1007.
Thereafter, the video information displayed on the monitor is outputted to the projector in a step S1011 in the same manner as that described above, and in a step S1012, the audio information read in the step S1006 is reproduced. At the same time, in a step S1013, the video information and the audio information are transmitted to the network.
When the image information is selected by the user, the process proceeds from the step S1008 to a step S1009 and the image information and the corresponding audio information are read into the computer. The read image information is displayed on the monitor in a next step S1010.
In the next step S1011, the image information displayed on the monitor is outputted to the projector and in a step S1012, the audio information read in the step S1009 is reproduced. At the same time, in a step S1013, the image information and the audio information are transmitted to the network.
On the other hand, a destination communication terminal in a lecture location receives the video information, the image information and the audio information which were transmitted to the network, displays them on a monitor or a projector and reproduces from a speaker. In this manner, the TV conference system and the remote lecturing system which includes the switching of input information by using terminals connected between remote stations through the network is attained.
On the other hand, in a conventional conference or lecture in which a lecturer and audience are at the same place and uses a blackboard or an OHP and does not use an electronic medium or communication, a presentator or lecturer manages by himself OHP sheets or a video tape to be used during the lecture so that he may check them at any time as required.
Accordingly, the switching of the materials to be used may be relatively smoothly conducted.
However, in the prior art remote lecturing system described above, it is necessary to switch the input information by depressing the switch 110 as shown in FIG. 11. Accordingly, a switching command from the user through the manipulation of the switch 110 is received by the computer so that only the commanded input information is displayed, outputted to the projector and transmitted to the network.
In this case, when the image information is to be utilized by depressing the xe2x80x9cDrawxe2x80x9d switch, the image information derived by reading the content of the OHP sheet is stored in the memory, not shown, as a file and each image information is sequentially read, displayed and transmitted by clicking a mouse. Accordingly, if the lecturer forgets the sequence of reading of the image information, he cannot identify the contents of the next image information to be transmitted.
When a draw tool is used instead of the OHP, the prepared image information is stored as the image file in a form of list and each of the image information is sequentially displayed by clicking the mouse. Accordingly, the lecturer again may not identify the contents of the next page.
When the video information from a camera of the video information from a video tape is to be used, the display or the transmission is conducted only when the switching of the input information is commanded by depressing a xe2x80x9cCameraxe2x80x9d switch or a xe2x80x9cVideoxe2x80x9d switch.
Accordingly, the lecturer cannot identify the video information to be displayed next.
As a result, in the prior art conference system or remote lecture system, the material or camera video image which the lecturer does not intend might be displayed or transmitted. In order to prevent such from occurring, it is necessary to repeat the sequence of the conference or lecture in rehearsal, which is time consuming and troublesome.
It is an object of the present invention to provide a communication terminal, a communication system and a communication method which solve the above problems.
It is another object of the present invention to provide a communication terminal, a communication system and a communication method which can selectively transmit a desired one of a plurality of information.
In order to achieve the above objects, in accordance with the present invention, there is provided a communication terminal device having input means for inputting each of a plurality of video information and a plurality of image information and output means for switching and outputting their input information, comprising display means for displaying a plurality of input information inputted by the input means and selection means for selecting any of the respective input information displayed by the display means. The input information selected by the selection means is switched by the output means for output.
It is other object of the present invention to provide a communication terminal, a communication system and a communication method having a new function.
Other objects and features of the present invention will be apparent from the following description of the preferred embodiments and the accompanying drawings.